Just for Fun: The Story of an Accidental Revolutionary is a humorous autobiography of Linus Torvalds, the creator of the Linux kernel, co-written with David Diamond. The book primarily theorizes the Law of Linus that all evolution contributed by humanity starts for survival, sustains socially and entertains at last. As well as this the book explains Torvalds' view of himself, the free software movement and the development of Linux.

Just for Fun has been translated into numerous languages including the first official language of Torvalds's home country Finnish, and later to his own first language Swedish (Torvalds is a member of the Swedish-speaking minority in Finland). The kernel that Torvalds started (and still maintains) for fun is now a part of the operating systems used by over 60 million people on the desktop, more in web services, even more on mobile devices.[1]